MCQ
The work function of a metal is $4.2 eV$, its threshold wavelength will be .......... $\mathop A\limits^o $
- A$4000$
- B$3500$
- ✓$2955$
- D$2500$
✓
Answer
Correct option: C.
$2955$
c
(c) ${W_0}(eV) = \frac{{12375}}{{{\lambda _0}}}\, $
(c) ${W_0}(eV) = \frac{{12375}}{{{\lambda _0}}}\, $
$\Rightarrow \,{\lambda _0} = \frac{{12375}}{{4.2}} \approx \,2955\,{Å}$
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